Zn-Coordinated Lipid Nanocapsules with High Physical Stability and Water-Responsive Morphological Change.

A novel lipid nanocapsule with high physical stability and the ability to undergo a water-responsive morphological change was prepared using a facile method from inexpensive and simple materials such as a glycylglycine-containing lipid and zinc acetate. The zinc-coordinated nanocapsule is comprised of solid bilayer membranes, which are stabilized by polyglycine-II type hydrogen-bond network and Zn-lipid coordination resulting in a high thermal stability in the dry state. The nanocapsules can easily encapsulate guest molecules such as methylene blue in the hollow space by dissolving the molecules in ethanol during preparation. When placed in an aqueous environment, the nanocapsules showed distinctive morphological changes and subsequent release of the methylene blue.